Layer-by-Layer Assembly of Nanofiber/Nanoparticle Artificial Skin for Strain-Insensitive UV Shielding and Visualized UV Detection

Here, a strain-insensitive, durable, and visualized ultraviolet (UV) detectible multilayered artificial UV shielding skin (MUVS-skin) is demonstrated. The electrospinning of polyurethane nanofibers and electrospraying of TiO₂ nanoparticles are alternatingly conducted to assemble the MUVS-skin. The results show that the stability of UV shielding property under different strains (50%, 100%, 150%, and 200%) is enhanced as more layers are assembled. The ultraviolet protection factor of the strain-free MUVS-skin (119 µm) is 10 810 and reaches to 5685 at 200% strain. Moreover, the effective transmittance (at 365 nm) of MUVS-skin (119 µm) after being stretched for 10 000 cycles at 200% strain is only 0.125%. This stable UV shielding property is ascribed to the low-level variation in the porosity of the multilayered structure, which originates from the enhanced slippage between adjacent layers. Furthermore, ultraviolet A (UVA) and ultraviolet B (UVB) can be precisely detected as the luminescence of blue and red for the MUVS-skin integrates with a phosphor layer (MUVS-skin/P). Owing to the excellent stable UV shielding property, visualized UV detection and durability against cyclic deformation, this MUVS-skin/P might be extensively applied to the smart wearable artificial skin and protective clothing.